1. Field of the Invention
The present invention pertains to electronic devices for use in harsh, demanding environments.
2. Description of the Related Art
The application of computing technology continues to expand into ever harsher environments. At one time, computers and other computing devices were housed in separate, dedicated, climate controlled rooms. People wishing to use such machines would go to where they were located to interact with them. Considerable effort was made to cater to the environmental needs of the machines, even to the point of inconveniencing the users. Accordingly, not much concern was given to designing computers and computing devices to withstand the rigors of harsh environments.
Increasing demands on computing technology have changed all that. Today, computing devices are being deployed in ever harsher environments with one or more conditions such as extreme temperatures, high shock, high vibration, excessive humidity, and chemical exposure. For instance, computers are commonly found in oilfield applications where they are subjected to extremes of temperature, shock and vibration'. Computing technology has also found growing application in military applications, including weapons systems that are particularly high performance. Military applications, as well as some civilian applications, also add the additional pressure of life and death stakes as a function of performance level.
Much effort has therefore gone into “ruggedizing” computing technology. Sometimes this results in changes to the designs of the computing devices, connectors, buses, storage devices, etc. For instance, the design of a microprocessor might be changed to enable to withstand higher or lower temperatures found in a particular harsh environment. Sometimes the effort results in techniques for installing an existing design. For example, an existing microprocessor might be mounted in a way that helps isolate it from vibration. Cumulatively, these kinds of changes significantly impact the performance of computing technology in demanding environments.
One complicating factor is the reality that ruggedization is but one factor in the design of a computing apparatus. The engineering task usually involves a multitude of tradeoffs among competing considerations that will be implementation specific. Thus, a particular ruggedization technique may not be acceptable if it results in excessive size and weight for, e.g., a missile whereas it may be acceptable if used in, e.g., an armored ground vehicle. Thus, it is not enough that a particular ruggedization technique is available and will work, it must also not force unacceptable tradeoffs with other engineering constraints. Preferably, the ruggedization technique will actually facilitate or enhance the design's ability to meet other engineering constraints. However, even if it facilitates the design effort in multiple areas, it may still be unacceptable if it undesirably impacts the computational performance of computing apparatus.
Another complicating factor is that the computing apparatus as a whole must be ruggedized. It does little good to ruggedize the computing device (e.g., the processor or controller) if the storage is not. Storage is equally important in the performance of a computing apparatus since the computing device is dependent upon the storage for, among other things, the data on which it operates. This becomes more important as computing technologies are applied to more computationally intensive problems that process higher volumes of data that require greater storage. Furthermore, the electrical connection between the computing device and the storage is dependent upon the buses and connectors through which the electrical connection is made. The ruggedization of each of these aspects of the computing apparatus involves different considerations such that techniques applicable to, for example, the computing device, may not be applicable to, for instance, the connectors.
To illustrate the difficulties of balancing these factors, consider the relatively recent development of removable mass storage. To facilitate portability, the mass storage device should be small and lightweight. To facilitate interoperability, the mass storage device should be relatively platform independent, i.e., to be usable with a variety of platforms. It should provide stable connections, high numbers of accesses, and fast accesses. For present purposes, it should be able to withstand extremes of temperature, high shock, high vibration, and high humidity. It should also cost relatively little.
Some “ruggedized” Universal Serial Bus (“USB”) flash drive, removable mass storage devices have been developed. These solutions are typically sufficiently small, light, and platform independent. Some have hardened packages for increased durability and, presumably, better tolerance for shock. However, they also employ the standard USB connector and interface. The standard USB interface is not suitable for military applications and for most harsh environments. Among other problems, the connectors are fragile and the connections they make are susceptible to failure in the face of high vibration and/or shock.
Some military solutions have been developed to address the deficiencies of these ruggedized USB flash drives. These solutions admirably address those deficiencies and are typically built on a removable flash card, such as a Compact Flash, Personal Computer Memory Card International Association (“PCMCIA”), etc. card. They generally include a host chassis with a removable cartridge assembly. However, they usually include a heavy internal power supply. They also tend to be bulky, large, expensive, and platform dependent.
The present invention is directed to resolving, or at least reducing, one or all of the problems mentioned above.